Loans and Leases and the Allowance for Loan and Lease Losses (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 D	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007
Aging Analysis of Accruing and Non-Accruing Loans and Leases
30 - 59 Days Past Due	$ 23,599	$ 24,634
60 - 89 Days Past Due	15,062	14,955
Past Due 90 Days or More	9,222	7,583
Non-Accrual	37,748	35,858
Total Past Due and Non-Accrual	85,631	83,030
Current	5,452,673	5,252,762
Total Loans and Leases	5,538,304	5,335,792	5,759,785	6,530,233	6,580,861
Non-Accrual Loans and Leases that are Current	8,578	12,930
Number of days non-accrual loans and leases are not past due	30
Commercial
Aging Analysis of Accruing and Non-Accruing Loans and Leases
30 - 59 Days Past Due	3,637	3,989
60 - 89 Days Past Due	743	1,341
Past Due 90 Days or More	1
Non-Accrual	10,468	5,452
Total Past Due and Non-Accrual	14,849	10,782
Current	2,151,168	2,040,549
Total Loans and Leases	2,166,017	2,051,331	2,157,926	2,416,652	2,379,390
Non-Accrual Loans and Leases that are Current	6,625	3,998
Commercial and Industrial
Aging Analysis of Accruing and Non-Accruing Loans and Leases
30 - 59 Days Past Due	2,959	1,807
60 - 89 Days Past Due	743	1,341
Past Due 90 Days or More	1
Non-Accrual	6,243	1,642
Total Past Due and Non-Accrual	9,946	4,790
Current	807,224	767,834
Total Loans and Leases	817,170	772,624	795,167	1,053,781	1,054,355
Non-Accrual Loans and Leases that are Current	5,661	1,564
Commercial Mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
30 - 59 Days Past Due	678	2,100
Non-Accrual	2,140	3,503
Total Past Due and Non-Accrual	2,818	5,603
Current	935,432	857,782
Total Loans and Leases	938,250	863,385	841,431	740,779	634,483
Non-Accrual Loans and Leases that are Current	959	2,415
Construction
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non-Accrual	2,080	288
Total Past Due and Non-Accrual	2,080	288
Current	96,589	80,037
Total Loans and Leases	98,669	80,325	108,395	153,952	208,670
Lease Financing
Aging Analysis of Accruing and Non-Accruing Loans and Leases
30 - 59 Days Past Due		82
Non-Accrual	5	19
Total Past Due and Non-Accrual	5	101
Current	311,923	334,896
Total Loans and Leases	311,928	334,997	412,933	468,140	481,882
Non-Accrual Loans and Leases that are Current	5	19
Consumer
Aging Analysis of Accruing and Non-Accruing Loans and Leases
30 - 59 Days Past Due	19,962	20,645
60 - 89 Days Past Due	14,319	13,614
Past Due 90 Days or More	9,221	7,583
Non-Accrual	27,280	30,406
Total Past Due and Non-Accrual	70,782	72,248
Current	3,301,505	3,212,213
Total Loans and Leases	3,372,287	3,284,461	3,601,859	4,113,581	4,201,471
Non-Accrual Loans and Leases that are Current	1,953	8,932
Residential Mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
30 - 59 Days Past Due	8,878	8,389
60 - 89 Days Past Due	9,258	9,045
Past Due 90 Days or More	6,422	5,399
Non-Accrual	25,256	28,152
Total Past Due and Non-Accrual	49,814	50,985
Current	2,166,078	2,043,204
Total Loans and Leases	2,215,892	2,094,189	2,190,677	2,461,824	2,486,284
Non-Accrual Loans and Leases that are Current	1,856	7,891
Home Equity
Aging Analysis of Accruing and Non-Accruing Loans and Leases
30 - 59 Days Past Due	5,310	4,248
60 - 89 Days Past Due	2,694	2,420
Past Due 90 Days or More	2,194	1,067
Non-Accrual	2,024	2,254
Total Past Due and Non-Accrual	12,222	9,989
Current	768,469	797,490
Total Loans and Leases	780,691	807,479	921,571	1,033,221	994,972
Non-Accrual Loans and Leases that are Current	97	1,041
Automobile
Aging Analysis of Accruing and Non-Accruing Loans and Leases
30 - 59 Days Past Due	4,095	6,046
60 - 89 Days Past Due	839	1,004
Past Due 90 Days or More	170	410
Total Past Due and Non-Accrual	5,104	7,460
Current	187,402	201,548
Total Loans and Leases	192,506	209,008	283,937	369,789	443,011
Other Consumer
Aging Analysis of Accruing and Non-Accruing Loans and Leases
30 - 59 Days Past Due	1,679	1,962
60 - 89 Days Past Due	1,528	1,145
Past Due 90 Days or More	435	707
Total Past Due and Non-Accrual	3,642	3,814
Current	179,556	169,971
Total Loans and Leases	$ 183,198	$ 173,785	$ 205,674	$ 248,747	$ 277,204